Evenness of shrinkage



'Patentecl Judy is. race in am;

acacia 'FHQ RID ELSSNER, OF J'bHNSOlS! TEISNESSEE, ASSIGNOR TO-AJWERICANGLANZ- STOFF COBPQBATION, OF NEW YORK, N. Y., A CORPORATION OF DELAW imass or smnaen 23o Drawing.

My present invention concerns a new methd of wet-treatingartificialfilaments i. e. filaments formed synthetically, specificallyfrom cellulosic solutions.

One object of my invention is to so wettreat filaments that an evenshrinkage results.

' For matter of convenience the present application is described withrespect to the viscose process, but it must be understood that my newinvention may be used in any process where spun filaments must 'bewettreated.

In the manufacture of filaments, and films,

M from a viscose solution, the extruded product is usually passedthrough an acid bath in order that it may be hardened, or ,precipitated.In the .case of artificial viscose filaments, for example, the productis usually wound upon foraminated or perforated spools or bobbins. Thefilaments must then be deacidified, desulphurized, and washed. Whendrying these yarns upon the perforated spools an uneven drying andshrinkage of the filaments usually results. This causes unevenness inthe quality of the yarn produced, and aifects the dyeing properties.According to my new process, a series-of dryings is accomplished, andthus an evenness of shrinkage results.

My process, with respect particularly to viscose yarns, for example, isas follows:

The yarn, wound upon a foraminated spool is wet-treated in the usualway, and then dried. The yarn body is then re-wet, and

dried. Then the filaments are rewound or twisted, onto another similarspool, in such a manner that a loose yarn body is obtained; and againwet and dried. Then a fourth w wetting and drying is performed and theresulting filaments have been found to possess a technically evenshrinkage and the corresponding desirable dyeing properties.

The drying may be accomplished in any {ell-known manner, and I do notwish to ave t eofd Iwishto'havem- 'ine ti dh limit dg fnly y v n pendedclaims. 1 The wetting may be accomplished by my present inventionlimited to any I by the scope of the ap- Application filed August 29,1931. Serial 1V0. 560,225.

spraying with water or aqueous solutions, H

or by dipping in water 'or aqueous solutions. claim:

1. In a process for treating wet artificial filaments wound upon a spoolor bobbin, the

steps of drying, rewetting and redrying the filaments, rewinding ontoanother spool or bobbin, rewetting, redrying, rewetting and redrying thefilaments.

2. In a process for'obtaining an evenness of shrinkage of spunfilaments, the steps of winding the same on a spool or bobbin,wettreating and drying, rewetting and 'redrying the same, rewinding ontoanother similar spool or bobbin, and repeating the 'wet: ting and dryinga plurality of times.

3. In'a process for obtaining an evenness of shrinkage of spunfilaments, the steps of -winding the same on a spool or bobbin,wettreating and drying, rewetting and redrying the same, rewinding andtwisting onto another similar spool, and repeating the wetting anddrying until altogether four dryingshave been performed.

4. In a process for obtaining an evenness of shrinkage of spunfilaments, the steps of winding the same on a spool or bobbin,wettreating, and drying, rewetting and redrying the same, rewinding ontoanother similar spool, and repeating the wetting and drying a pluralityof times while thereon.

In testimony whereof I aflix my signature.

' DR. RICHARD ELSSNER.

